It was glaringly apparent to anyone who watched Aaron Rodgers and the Green Bay Packers crater in 2018 that the coach wasn’t getting through to either his quarterback or the rest of his team. Still, the way in which Mike McCarthy’s Green Bay tenure ended came as a shock.

He was fired on Dec. 2 — Rodgers’s birthday — after a dismal 20-17 home loss to the Arizona Cardinals dropped the Packers to 4-7-1.

“It couldn’t have been handled any worse. Anytime you lose a close game, it’s a difficult time emotionally afterward, but when you lose a home game at Lambeau Field in December, it’s really hard. And that hasn’t happened very often,” McCarthy said in an interview with ESPN’s Rob Demovsky published Wednesday. “I walked out of my press conference, and I’m thinking about the game, thinking about how our playoff shot was now minimal. That’s where my head was at. And when I was told Mark Murphy [the team’s president and CEO] wanted to see me — and the messenger was cold and the energy was bad. Mark said it was an ugly loss, and it was time to make [a] change. He said something about the offense and the special teams, and he didn’t think it was going to get any better. There was no emotion to it. That was hard.”

McCarthy was in the midst of his 13th season with a team that doesn’t change coaches on a whim, even if it was teetering on the brink of missing the playoffs. And so the former coach admitted that the “exit stuck with me for a while. It was hard to swallow,” he added.

“The emotional challenge of shifting from humiliation to reflection was a very important step in seeking clarity so I could personally grow from the experience of my entire Green Bay Packer career; that’s what I wanted to get to, not just the ending of it."

McCarthy went 125-77-2 with the Packers and failed to make the playoffs four times (including 2018), but there was a perception that his play-calling and relationship with Rodgers had frayed since producing a Super Bowl victory in 2011, and that the team was wasting the best years of the quarterback’s career. There were whispers about Rodgers being unsatisfied with McCarthy’s play-calling, and the quarterback seemed to offer thinly veiled criticism of the game plan after Green Bay’s 22-0 victory over Buffalo in Week 4.

McCarthy said he was “not aware” of any sideline comments and pointed out that Rodgers always was “heavily involved in game-planning each week and scheme design each year. I entrusted him and empowered him more than any other quarterback I’ve ever been around, especially at the line of scrimmage.

“As far as our relationship, you have to put it through the proper lens like you always have to do with reflection and change,” he told Demovsky. “Where there’s change, let’s be real, especially the way the change happened, there’s things that come out after the fact. Things get said. He-said, he-said this, and things like that. When I think about my relationship with Aaron, you’re talking about 13 years. That’s a very long time. It’s been a privilege to watch him grow in so many different ways and see him do so many great things on the field and off. To think you can be in a relationship that long and not have any frustrations, that’s unrealistic.”

Rodgers turned 35 in December, meaning he is far closer to the end of his career than to the beginning, even if he has said he hopes to play past 40.

“As far as coaching him, I’d use a lot of words. He’s challenging, very rewarding and fun. We had a lot of fun,” McCarthy told Demovsky. “Some of my greatest one-on-one conversations, accomplishments, adjustments and adversity we fought through have been with Aaron. The difficulty in coaching a Hall of Fame quarterback is keeping that connection, the efficiency and the fluency with the other players on offense. They want to do more. They’re capable of doing so much more, but the reality is you have to remember is it’s the coordination of 11 men on every play.

“But yeah, it’s pretty fun to go through your entire offensive playbook and know you can run everything in there with your quarterback. I mean, that’s a joy. His job was to score as many points as he can. My job was to make it all work.”

Rodgers’s discontent last season appeared to be months in the making. “My quarterback coach didn’t get retained,” Rodgers said in February 2018, referring to the decision to part with Alex Van Pelt. “I thought that was an interesting change — really without consulting me. There’s a close connection between quarterback and quarterback coach. And that was an interesting decision.”

And it helped set the stage for more disappointments to come. As for McCarthy today, he had hoped to be coaching the New York Jets now. Instead, he waits at his Green Bay home for his next opportunity. There have been frustrations, including a report about him berating referees at his stepson’s high school basketball game, something for which he has apologized.

His former team will begin offseason work next week under Matt LaFleur, the head coach who says he has met Rodgers only once. LaFleur will be tasked with fixing whatever was wrong — and doing so quickly. Last year, Sports Illustrated’s Andy Benoit speculated in November that the problem for Rodgers may lie with a style that “creates an illusion of dysfunction around him.” Rodgers scrambles and invents plays, and the line or the coach get the blame when they fail. Ryan Wood of Packers Wire pointed out that “Rodgers is greedy when he doesn’t need to be,” often refusing to take “the path of least resistance [as he] tries to jam his outdated style of playing quarterback into an offense just begging for a trustworthy distributor.”

LaFleur has a reputation of working well with quarterbacks, and he knows that he and the NFL’s highest-paid player must make their partnership work.

“I know how important our relationship is going to be. It’s more or less getting to know the person,” LaFleur said on “The Adam Schefter Podcast” recently. “I can’t wait to really sit down and dive into the football component.”

Cindy BorenCindy Boren arrived at The Post in 2000 as an assignment editor in charge of baseball and NFL/Redskins coverage. She switched to full-time writing, focusing on national sports stories and issues, when she founded The Early Lead blog in 2010. Follow